Introduction [You must be registered and logged in to see this link.] FinalGen is a chess endgame tablebase generator for Windows.
FinalGen is absolutely free. You can distribute the freeware version of
this software providing that no additional fee is charged.
Endgame tablebases An endgame tablebase is a computerized database that contains
precalculated exhaustive analysis of a chess endgame position.
The tablebase contains the game-theoretical value (win, loss, or draw)
of each possible move in each possible position, and how many moves it
would take to achieve that result with perfect play.
Tablebases have solved chess for every position with six or fewer pieces
(including the two kings). The whole set of tables requires 1153 GB of
hard disk space. Some seven-piece positions have been produced as well.
Chess programs Most of the time, modern chess programs play endgames well, but in some
situations they exhibit a glaring weakness, as we will see later.
Most engines can consult tablebases as a kind of oracle to decide
whether to exchange down into an endgame covered by the tablebase. A
chess engine can for example avoid exchanging down to losing positions
(even if they are very deep) or win by converting into an absolutely won
endgame.
The tablebases of all endgames with up to six pieces are available for
free download. Unfortunately, Nalimov tablebase requires more than one
terabyte of storage space.
What advantage has FinalGen over chess programs and Nalimov tableblases?
Unlike Nalimov tablebases, FinalGen is able to solve chess positions
with 7 or more pieces. All examples presented here include more than 6
pieces on the chessboard (including the kings). Unlike chess programs,
FinalGen produces the game-theoretical value (win, loss, or draw) rather
than a mere evaluation.
Eiko Bleicher has designed a commercial program called
Freezer,
which allows users to build new tablebases from existing Nalimov
tablebases with a priori information. The program can produce a
tablebase for seven-piece positions with blocked pawns. FinalGen
generates tablebases without any kind of a priori information.
Example 1: when computers are wrong
Number of pieces: 7. Execution time: 35 minutes.
The machine we used to generate these examples was a standard AMD Athlon
3500+ system with Windows XP installed and an external disk drive.
We also allowed Fritz 11 to analyse this position. Fritz 11, running on a
single core gets you more than 1 million positions per second. 35
minutes later, the result was:
d4 -2.47
Nd4 -0.79
Ne7 -0.79
Ke6 -0.79
Nh4 -0.71
Ng7 -0.71
Kd8 0.00
Kc8 0.00
Ke8 0.00
Ke7 0.00
Ng3 +11.88
Nh6 +12.85
Ne3 +15.20
Nd6 +15.71
As you can see, Fritz considers d4 to be a winning move, whereas FinalGen found only a draw for this move.
The reason is that Black captures the white pawn in the most direct way
by playing d4, but black pawns become weak and the black knight is tied
down to the defence of the d-pawn.
A possible continuation will proceed:
1... d4 2. Kb4 Ne3 3. Be5 d3 4. Bc3 Nf1 5. Kb3 Ke6 6. Bg7 Kd5 7. Kc3 d2 8. Kc2 Kxc5 9. Bc3 Kd5 10. Bf6 (White must not take the pawn) Ng3 11. Ba1
(White has not played the most accurate moves, allowing Black to
improve the placement of its knight, but this is not enough for winning)
Ne4 12. Kd1 Kc4 13. Kc2 c5 14. Bg7 Kb4 15. Ba1 c4 16. Bh8 Kc5 17. Bg7 Kd5 18. Bh8 Ke6 19. Ba1 Kf5 20. Kd1 Kf4 21. Ke2 and Black cannot win.
It is interesting to notice that Fritz has evaluated some winning moves
to be only 0.79 pawns better for Black, which is not definitive. Also
notice that Fritz considers all king moves to be a draw.
What are the disadvantages of FinalGen?Generating tablebases for positions with 8 or more pieces can be a long, time consuming process.
The time required to generate tablebases depends strongly on the number
of pieces and the characteristics of the position. For 7-piece
positions, the process can take between 30 minutes and 3 hours (with an
AMD Athlon 3500+ processor).
FinalGen reaches its maximum efficiency when solving pawn endings. For
instance, one hour can be required to solve a position with two kings
and 6 or 7 pawns.
Notice that the amount of calculated positions for each endgame with
more than 6 pieces grows to astronomical numbers (billions of positions
for 7 pieces endgames).
However, when the process is finished, the analysis of all variations
can be obtained almost instantaneously. FinalGen stores the evaluations
of all positions that can be reached from the initial one by making
legal chess moves.
A major limitation of FinalGen
is that it can only manage endgames with up to one minor or major piece
per side, and any number of pawns. Consequently, endgames in which there
are 3 knights and king versus a king cannot be solved.
FinalGen has been designed to analyse practical chess endings. Normally
you would never end up with 3 knights since you would make your promoted
pawn a queen. This kind of endgame is probably of interest only to
chess problem hobbyists.
Instead, it is more likely that you play an endgame with a rook and two
pawns versus a rook and two pawns. In this situation you can use
FinalGen to generate the tablebases for the position. The process will
take some hours for an 8-piece position (or dozens of hours depending on
the characteristics of the position).
Example 2Number of pieces: 10. Execution time: 1 hour and 42 minutes.One of the most famous positions solved with the method of
corresponding squares is this endgame study composed by N. Grigoriev.
If squares x and y are corresponding squares, it means that if one
player moves to x then the other player must move to y in order to hold
his position. In some cases they indicate which square the defending
king must move to in order to keep the opposing king away. In other
cases, a maneuver by one king puts the other player in a situation where
he cannot move to the corresponding square, thus the first king is able
to penetrate the position. The theory of corresponding squares is more
general than opposition, and is more useful in cluttered positions.
FinalGen is particularly efficient for solving this kind of position.
The tablebases for this 10-pieces position were generated in 1 hour and
42 minutes.
We also let Fritz 11 do an infinite analysis on this position. After
letting the program run for over 1 hour and 40 minutes, Fritz gave the
following evaluations:
Kd1 +2.76
Kd2 +1.99
Kb2 +1.84
Kc2 +1.84
Kb1 +1.84
axb5 +1.61
a5 0.00
As you can see, Fritz considers that:
- Kd1 is the best move (which is true).
- Kd1, Kd2, Kb2, Kc2, Kb1 and axb5+ are all winning moves, which is
false. Only Kd1 can force a win. The other moves result only in a draw.
In this ending, c5, d5, and g6 are
key squares. If the white king can reach any of them, White wins.
If the white king moves to e4, then the black king must move to d6 in
order to prevent White from occupying the key square d5. Remark: Moving
to c6 allows the white king to reach g6.
With separated key squares, the shortest path connecting them is
significant. If the white king moves to d4, then the black king must
move to c6, and so on. The corresponding squares are: d4-c6, e4-d6,
d3-c7, e3-d7, f3-e7, d2-c8, e2-d8 and f2-e8.
Thus the general formula is as follows: the white king has the
opposition when he occupies, on a right hand adjacent file to the file
occupied by the black king, a square of opposite colour to that occupied
by the latter.
If the white king manages to reach the g6 key square, then Black can react in two ways:
1. Attacking the white pawns on the queenside. In that case, both sides
will have single passed pawns racing to promote to a queen. Before
occupying g6 White must ensure that he/she will win the resulting queen
ending.
2. Moving toward the kingside and occupying e4 when the white king reaches g6. White can avoid zugzwang by playing a5.
Now we know the main characteristics of the position. White wins in two steps:
Step 1: taking the opposition.
1. Kd1 Kd7 2. Ke1 Ke7 3. Kd2 Kd8 4. Ke2 Ke8 5. Kd3 Kd7 6. Ke3 Kd6 7. Ke4 Kc6
Step 2: winning the race to promotion.
8. Kf3 Kd5 9. Kg3! (9. Kg4? Ke4=) Kd4 10. Kh4 Kc3 (10... Ke4 11. Kg4 Ke3 12. Kh5 Kxf4 13. Kg6 Ke5 14. a5 +-) 11.
axb5 axb5 12. Kh5 Kxb4 13. Kg6 Kxb3 14. Kxf6 Kc3 15. Ke5 b4 16. f6 b3
17. f7 b2 18. f8=Q b1=Q 19. Qc5+ Kd2 20. Qf2+ Kc3 21. Qd4+ exchanges queens and wins.
The evaluation of a position Unlike chess programs, FinalGen produces the game-theoretical value
(win, loss, or draw) rather than a mere evaluation. The tablebases are
generated by retrograde analysis, working backwards from checkmated
positions.
Nalimov tables give the number of moves to the end of a game with best
play. It is easy to play perfectly by looking up such a table.
In most cases, FinalGen gives a way to win too, but not necessarily the shortest one. For example, Finalgen might predict
Win in 12 moves in a case where Nalimov tablebases indicate
Win in 10 moves.
There is no notion of perfect play for a game which ends in a tie. Such a
game is merely considered equivalent to a game which goes on forever
because neither player can force a victory.
Not all positions can be solved by FinalGen. Sometimes, White or Black
can force the promotion of a pawn, transposing into a different endgame
that FinalGen cannot solve. In that case, the text
Not available will be displayed. These unsolvable positions represent about 5% of all positions that can be generated.
Other times, after a pawn gets promoted, the position transposes into an
endgame that FinalGen can solve. In such situations, the displayed
result can be
White wins or
Black wins without
specifying a number of moves. These positions are stored as bitbases
which give the game-theoretical value of positions without the number of
moves until promotion or mate.
When available, the evaluation of a position can be one of the following:
- "White wins. Mate." The black king is checkmated.
- "White mates in X." White checkmates in X moves.
- "White wins in X." A white pawn can promote in X moves, and White can force a win.
- "White wins." White wins, the number of moves is not known.
- "White does not lose." White can win or draw.
- "Draw."
- "Black does not lose", "Black wins", "Black wins in X", "Black mates in X", "Black wins. Mate". Analogous to the previous ones from black side.
Example 3Number of pieces: 8. Execution time: 10 minutes with Search for draw option activated.This is a study by A. Nimzowitsch. It is often used to illustrate the
technique to win in a knight vs bishop endgame with blocked pawns. The
"winning" plan is typically to expel the black king from light squares
by delivering checks with the knight, thus allowing the white king to
penetrate the position.
However, after generating the tablebases, we can see that the position is a draw with perfect play.
Let us take a look at the main line proposed by the author:
1. Nh4+ Kf6 2. Kh5 Bc7 3. Nf3 Ba5 4. Nh2 Bc3 5.
Ng4+ Ke6 6. Kg6 Bd4 7. Nf6 Be3 8. Nh7 Bd4 9. Ng5+ Kd6 10. Kf5 Bc3 11.
Nf7+ Kc6 12. Ke6 Bb2 13. Nxe5+ Kc7 14. Ng6 Kd8 15. Kf7 1-0.
After some moves
(1. Nh4+ Kf6 2. Kh5 Bc7 3. Nf3 Ba5 4. Nh2)
FinalGen still considers the result to be a draw. The move 4... Bc3 is
the blunder that cost the game. Black should have continued with
4... Bd2 (or Bd8) 5. Ng4+ Kf7 6. Nxe5+ Kf6 7. Nd3 Ke6 8. Kg4 Be3 9. Kf3 Bg1 10. Kf4 Bh2+ 11. Kf3 Bg1 12. e5 Kf5 13. Kg3 Bd4 ½-½.
Features- FinalGen generates tablebases for chess endgames with up to one piece per side, and any number of pawns.
- The
Search for draw option
allows speeding up the process. When enabled, this option will search
only for drawn results, but can run up to 10 times faster.
- The analysis area allows displaying variations.
- You can pause and resume the process at any time.
- FinalGen displays statistic information such as the estimated time remaining, the required hard disk space and the number of positions calculated.
- Available interface languages: English, French, Spanish.
System requirements - Pentium 4, equivalent or better, AMD Athlon 64 or better. FinalGen
supports all INTEL processors released after 2000 and AMD processors
introduced after 2003.
- 1 Gigabyte of RAM.
- Windows 2000/XP/Vista/7.
- The required hard disk space depends on the characteristics of each
particular position. A reasonable amount of disk space is 80GB (or 30GB
if you use a compressed folder).
Compressing your working folder is strongly recommended. This can help you save a lot of time and disk space.
To compress the working folder, right-click the folder you want to compress, and then click
Properties. On the
General tab, click
Advanced.
Select the
Compress contents to save disk space check box, and then click
OK.
Please, click the button below to download FinalGen tablebase generator. [You must be registered and logged in to see this link.] FinalGen is absolutely free. However, if this program is useful to you, you can support its development by making a donation.
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